Acrylamide-containing photo active co-solvents

ABSTRACT

The present disclosure is drawn to an acrylamide-containing photo active co-solvent, including a bis-tris propane co-solvent or a polypropylene oxide amine co-solvent modified with an acryloyl group to form the acrylamide-containing photo active co-solvent.

BACKGROUND

Recently, curing of ink by radiation, and in particular ultraviolet (UV)curing, has become popular. UV curable ink can be cured after printingby application of UV light. Typically, UV curable inks include monomersthat form polymers by free radical polymerization. The growing end ofeach polymer chain is a radical that reacts with additional monomers,transferring the radical to the end of the chain as each monomer isadded. A photo initiator can be used to form first radicals to begin thepolymerization process. The photo initiator can be capable of absorbingUV light to generate radicals to react with the monomers.

Two types of photo initiators can be used in UV curable compositions.Type I photo initiators are unimolecular photo initiators that undergo ahemolytic bond cleavage upon absorption of UV light, forming radicals.Type II photo initiators are bimolecular photo initiators. These areused as a system of a photo initiator with a synergist, which cantogether form radicals upon exposure to UV light. Some Type II photoinitiators react by hydrogen abstraction from the synergist to the photoinitiator.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 provides an example of a general formula depicting the conversionof a base compound to a photo active co-solvent by reaction with anacryloyl halide, such as an acryloyl chloride; and

FIG. 2 provides an example method of making a photo curable ink inaccordance with the present disclosure.

DETAILED DESCRIPTION

The inkjet printing industry uses various types of inks, such asoil-based inks, solvent-based (non-aqueous) inks, water-based (aqueous)inks, and solid inks which are melted in preparation for dispensing.Solvent-based inks are fast drying, and as a result, are widely used forindustrial printing. When solvent-based inks containing binders andother ingredients are jetted onto a substrate, the solvent(s) partiallyor fully evaporate from the ink, leaving the binder and otheringredients such as pigment particles on the printed substrate in theform of a dry film. During the drying process, the solvents, which areoften volatile organic compounds (VOC), emit vapors, and therefore, canpollute the environment. The amount of pollution produced can increasegreatly with higher printing speeds or for wide format images, wherelarge amounts of ink are deposited onto a substrate.

As a result of this and other concerns, efforts related to preparinginks that are environmentally friendly have moved some research in thedirection of water-based inks. However, radiation curable (or photocurable) water-based ink compositions are noticeably limited amongavailable options of photo active co-solvents due to their specificformulation properties. For example, even though one can use dispersionsof photo initiators along with a dispersant, there can becrystallization issues that get introduced at high concentrations in theink. Thus, it would be desirable to develop water soluble or watercompatible photo active materials, including those that may also bephysically and/or chemically stable in photo curable ink formulations.

One such photo active material that can be used is a photo activeco-solvent that is compatible in water-based systems, and which canparticipate in polymerization under exposure to UV energy. The photoactive co-solvent described herein can be admixed with water and otherco-solvent, or as part of a co-solvent package. These photo activeco-solvents can be water soluble and/or water stable in a basicenvironment, and furthermore, can be reactive in photo curable inkformulations, for example. Their stability can be in part due to thepresence of an acrylamide linkage. In addition to being stable in theink, these photo active co-solvents can be cross-linkable under UV-LEDexposure, making them non-VOC, and contributing to the high durabilityof inks in which these co-solvents are included. In one example, thesephoto active co-solvents can work together with photo active binders toprovide enhanced durability in some cases than with respect to the useof the photo curable binder alone.

Accordingly, the present disclosure is drawn to an acrylamide-containingphoto active co-solvent, which can include a bis-tris propane co-solventor a polypropylene oxide amine co-solvent modified with an acryloylgroup to form the acrylamide-containing photo active co-solvent. In oneexample, the polypropylene oxide amine can also include polyethyleneoxide groups. Example structures are shown at Formulas I to VI below. Inother examples, the acrylamide-containing photo active co-solvent caninclude multiple acrylamide groups. In another example, theacrylamide-containing photo active co-solvent can include a secondaryamide. In still another example, the acrylamide-containing photo activeco-solvent can include a tertiary amide.

The present disclosure also provides a photo curable ink. The ink caninclude a photo reactive binder; a photo initiator; a co-photoinitiator, a synergist, or combination thereof; a colorant; and a liquidvehicle including water and a bis-tris propane co-solvent or apolypropylene oxide amine co-solvent reacted with an acryloyl group toform an acrylamide-containing photo active co-solvent. In one example,the acrylamide-containing photo active co-solvent can include asecondary amide. In another example, the acrylamide-containing photoactive co-solvent can include a tertiary amide. In yet another example,the acrylamide-containing photo active co-solvent can include multipleacrylamide groups.

In another example, a method of preparing a photo curable ink caninclude mixing a photo reactive binder; a photo initiator; a co-photoinitiator, a synergist, or combination thereof; a colorant; and a liquidvehicle including water and an acrylamide-containing photo activeco-solvent including a bis-tris propane co-solvent or a polypropyleneoxide amine co-solvent reacted with an acryloyl group.

In further detail as it relates to the photo active co-solvents of thepresent disclosure, these co-solvents can be prepared by reacting a basecompound co-solvent with an acryloyl halide (e.g., acryloyl chloride) toform a photo active co-solvent in accordance with the presentdisclosure, as shown at FIG. 1.

Example of Photo Active Co-solvents that can be prepared in accordancewith FIG. 1 include the following:

where each x can be independently from 1 to 70, and y can be from 1 to40. In one example, each x can independently be from 2 to 30 or from 4to 10. In another example, y can be from 2 to 30 or from 4 to 10.

Scheme 1 shows the preparation of Photo Active Co-solvent I from thecommercially available starting material bis-tris propane by reactionwith acryloyl chloride in THF and TEA at 0° C.

Schemes 2 through 6 show six additional examples of preparing PhotoActive Co-solvents (2-6), where the Starting Base Compound are based onJeffamine® polyetheramines, available from Huntsman Chemical. Jeffamine®polytheramines contain primary amino groups attached to the end ofvarious polyether backbones. The polyether backbones are normally basedon polypropylene oxide (PPO), but can also further include polyethyleneoxide (PEO). These compounds are generally water soluble. Introductionof curable acryloyl groups (from an acryloyl halides) into theseJeffamine® base compounds result in various Photo Active Co-solvents.

Scheme 2 depicts the synthesis of a Photo Active Co-solvent II (JA-MA)from Jeffamine® M by the reaction with acryloyl chloride in THF/TEA at0° C., followed by treatment of sodium bicarbonate.

In Scheme 2, x can be from 1 to 70, and y can be from 1 to 40. In oneexample, x can be from 2 to 30 or from 4 to 10. In another example, ycan be from 2 to 30 or from 4 to 10.

Scheme 3 depicts the synthesis of a Photo Active Co-solvent III (JA-DDA)from Jeffamine® D by the reaction with acryloyl chloride in THF/TEA at0° C., followed by treatment of sodium bicarbonate.

In Scheme 3, x can be from 1 to 70. In one example, x can be from 2 to30 or from 4 to 10.

Scheme 4 depicts the synthesis of a Photo Active Co-solvent IV (JA-900DA) from Jeffamine® JA-900 by the reaction with acryloyl chloride inTHF/TEA at 0° C., followed by treatment of sodium bicarbonate.

In Scheme 4, each x can independently be from 1 to 70, and y can be from1 to 40. In one example, each x can independently be from 2 to 30 orfrom 4 to 10. In another example, y can be from 2 to 30 or from 4 to 10.

Scheme 5 depicts the synthesis of a Photo Active Co-solvent V (JA-T-403TA) from Jeffamine® JA-T-403 by the reaction with acryloyl chloride inTHF/TEA at 0° C., followed by treatment of sodium bicarbonate.

In Scheme 5, each x can independently be from 1 to 70. In one example,each x can independently be from 2 to 30 or from 4 to 10.

Scheme 6 depicts the synthesis of a Photo Active Co-solvent VI (JA-XTJDA) from Jeffamine® XTJ by the reaction with acryloyl chloride inTHF/TEA at 0° C., followed by treatment of sodium bicarbonate.

In Scheme 6, x can be from 1 to 70. In one example, x can be from 2 to30 or from 4 to 10.

The present disclosure also extends to photo curable inks, such as UVcurable inks including LED curable inks. In some examples, a photocurable ink can include a photo reactive binder (such as a UV curable orLED curable binder), a photo active co-solvent, a photo initiator, aco-photo initiator and/or a synergist, a colorant, a co-solvent, andwater. The photo active co-solvent(s) can be as described herein, and asexemplified in Formulas I to VI, and in Schemes 1 to 6. As mentioned,these co-solvents can be water stable in a basic environment, reactivein photo curable ink formulations, cross-linkable under UV-LED exposure,and contribute to the high durability of photo curable inks generally.In one example, these photo active co-solvents can work together withphoto active binders to provide enhanced durability compared to inkswithout these photo active co-solvents, particularly is it may relate toscratch resistance.

With respect to the photo reactive binder, these materials can include aUV or LED curable polyurethane (cPUD) and/or hydrophobicradiation-curable monomers. In one example, the UV reactive binder caninclude a water dispersible (meth)acrylated polyurethane, such asNeoRad® R-441 by NeoResins (Avecia). Other examples of UV reactivebinders can include Ucecoat® 7710, Ucecoat® 7655 (available from Cytec),Neorad® R-440, Neorad® R-441, Neorad® R-447, Neorad® R-448 (availablefrom DSM NeoResins), Bayhydrol® UV 2317, Bayhydrol® UV VP LS 2348(available from Bayer), Lux 430, Lux 399, Lux 484 (available fromAlberdingk Boley), Laromer® LR 8949, Laromer® LR 8983, Laromer® PE 22WN,Laromer® PE 55WN, Laromer® UA 9060 (available from BASF), orcombinations thereof.

The photo initiators or co-photo initiators can act as a Type I or aType II photo initiator. Thus, the photo curable ink can include asensitizer component and/or a synergist. In the case of the synergist,an amine synergist can be used, for example. The photo initiator andsynergist together can generate radicals during photo curing, such aswith UV curing or even LED curing processes. The synergist can be atertiary amine compound. In one example, the synergist can be apolymeric amine synergist such as a derivative of aniline and apolyether amine such as Jeffamine® 900. In other examples, the synergistcan be trimethylamine, triethanolamine, methyldiethanolamine,phenyldiethanolamine, N,N,N′,N′-tetra(hydroxylethyl)ethylenediamine,dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethyldimethylaminobenzoate, or combinations thereof.

As mentioned, the first or second photo initiator can act as a primaryphoto initiator in the photo curable ink, or can act as a sensitizer foranother photo initiator. Therefore, the photo curable ink can in somecases include a second photo initiator in addition to the photoinitiators disclosed herein. Examples of radical photo initiators(either as a primary, secondary, or sensitizer photo initiator) include,by way of illustration and not limitation,1-hydroxy-cyclohexylphenylketone, benzophenone,2,4,6-trimethylbenzo-phenone, 4-methylbenzophenone,diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, phenyl bis(2,4,6trimethylbenzoyl)phosphine oxide,2-hydroxy-2-methyl-1-phenyl-1-propanone, benzyl-dimethyl ketal,2-methyl-l-[4-(methylthio)phenyl]-2-morpholinopropan-l-one, orcombinations thereof. Non-limiting examples of additional photoinitiators include alpha amino ketone UV photo initiators such as Ciba®Irgacure® 907, Ciba® Irgacure® 369, and Ciba® Irgacure® 379; bisacylphosphine oxide (BAPO) UV photo initiators such as Irgacure® 819,Darocur® 4265, and Darocur® TPO; alpha hydroxy ketone UV photoinitiators such as Irgacure® 184 and Darocur® 1173; including photoinitiators with or without sensitizers such as Darocur® ITX (2-isopropylthioxanthone).

The colorant in the photo curable ink can be a pigment, a dye, or acombination thereof. In some examples, the colorant can be present in anamount from 0.5 wt % to 10 wt % in the photo curable ink. In oneexample, the colorant can be present in an amount from 1 wt % to 5 wt %.In another example, the colorant can be present in an amount from 5 wt %to 10 wt %.

In some examples, the colorant can be a dye. The dye can be nonionic,cationic, anionic, or a mixture of nonionic, cationic, and/or anionicdyes. Specific examples of dyes that can be used include, but are notlimited to, Sulforhodamine B, Acid Blue 113, Acid Blue 29, Acid Red 4,Rose Bengal, Acid Yellow 17, Acid Yellow 29, Acid Yellow 42, AcridineYellow G, Acid Yellow 23, Acid Blue 9, Nitro Blue Tetrazolium ChlorideMonohydrate or Nitro BT, Rhodamine 6G, Rhodamine 123, Rhodamine B,Rhodamine B Isocyanate, Safranine O, Azure B, and Azure B Eosinate,which are available from Sigma-Aldrich Chemical Company (St. Louis,Mo.). Examples of anionic, water-soluble dyes include, but are notlimited to, Direct Yellow 132, Direct Blue 199, Magenta 377 (availablefrom Ilford AG, Switzerland), alone or together with Acid Red 52.Examples of water-insoluble dyes include azo, xanthene, methine,polymethine, and anthraquinone dyes. Specific examples ofwater-insoluble dyes include Orasol® Blue GN, Orasol® Pink, and Orasol®Yellow dyes available from Ciba-Geigy Corp. Black dyes may include, butare not limited to, Direct Black 154, Direct Black 168, Fast Black 2,Direct Black 171, Direct Black 19, Acid Black 1, Acid Black 191, MobayBlack SP, and Acid Black 2.

In other examples, the colorant can be a pigment. The pigment can beself-dispersed with a polymer, oligomer, or small molecule; or can bedispersed with a separate dispersant. Suitable pigments include, but arenot limited to, the following pigments available from BASF: Paliogen®Orange, Heliogen® Blue L 6901F, Heliogen® Blue NBD 7010, Heliogen® BlueK 7090, Heliogen® Blue L 7101F, Paliogen® Blue L 6470, Heliogen® Green K8683, and Heliogen® Green L 9140. The following black pigments areavailable from Cabot: Monarch® 1400, Monarch® 1300, Monarch® 1100,Monarch® 1000, Monarch® 900, Monarch® 880, Monarch® 800, and Monarch®700. The following pigments are available from CIBA: Chromophtal® Yellow3G, Chromophtal® Yellow GR, Chromophtal® Yellow 8G, Igrazin® Yellow 5GT,Igrantee Rubine 4BL, Monastral® Magenta, Monastral® Scarlet, Monastral®Violet R, Monastral® Red B, and Monastral® Violet Maroon B. Thefollowing pigments are available from Degussa: Printex® U, Printex® V,Printex® 140U, Printex® 140V, Color Black FW 200, Color Black FW 2,Color Black FW 2V, Color Black FW 1, Color Black FW 18, Color Black S160, Color Black S 170, Special Black 6, Special Black 5, Special Black4A, and Special Black 4. The following pigment is available from DuPont:Tipure® R-101. The following pigments are available from Heubach:Dalamar® Yellow YT-858-D and Heucophthal Blue G XBT-583D. The followingpigments are available from Clariant: Permanent Yellow GR, PermanentYellow G, Permanent Yellow DHG, Permanent Yellow NCG-71, PermanentYellow GG, Hansa Yellow RA, Hansa Brilliant Yellow 5GX-02, HansaYellow-X, Novoperm® Yellow HR, Novoperm® Yellow FGL, Hansa BrilliantYellow 10GX, Permanent Yellow G3R-01, Hostaperm® Yellow H4G, Hostaperm®Yellow H3G, Hostaperm® Orange GR, Hostaperm® Scarlet GO, and PermanentRubine F6B. The following pigments are available from Mobay: Quindo®Magenta, Indofast® Brilliant Scarlet, Quindo® Red R6700, Quindo® RedR6713, and Indofast® Violet. The following pigments are available fromSun Chemical: L74-1357 Yellow, L75-1331 Yellow, and L75-2577 Yellow. Thefollowing pigments are available from Columbian: Raven® 7000, Raven®5750, Raven® 5250, Raven® 5000, and Raven® 3500. The following pigmentis available from Sun Chemical: LHD9303 Black. Any other pigment and/ordye can be used that is useful in modifying the color of the UV curableink. Additionally, the colorant can include a white pigment such astitanium dioxide, or other inorganic pigments such as zinc oxide andiron oxide.

The components of the photo curable ink can be selected to give the inkgood ink jetting performance. Besides the photo curable binder, photoactive co-solvents, photo initiator(s), sensitizer, amine synergist,and/or the colorant, the photo curable ink can also include a liquidvehicle. Liquid vehicle formulations that can be used in the photocurable ink can include water and one or more co-solvents (other thanthe photo active co-solvent) present in total at from 1 wt % to 50 wt %,depending on the jetting architecture.

Classes of co-solvents (in addition to the photo active co-solvent) thatcan be used can include organic co-solvents including aliphaticalcohols, aromatic alcohols, diols, glycol ethers, polyglycol ethers,caprolactams, formamides, acetamides, and long chain alcohols. Examplesof such compounds include primary aliphatic alcohols, secondaryaliphatic alcohols, 1,2-alcohols, 1,3-alcohols, 1,5-alcohols, ethyleneglycol alkyl ethers, propylene glycol alkyl ethers, higher homologs(C₆-C₁₂) of polyethylene glycol alkyl ethers, N-alkyl caprolactams,unsubstituted caprolactams, both substituted and unsubstitutedformamides, both substituted and unsubstituted acetamides, and the like.Specific examples of solvents that can be used include, but are notlimited to, 2-pyrrolidinone, N-methylpyrrolidone,2-hydroxyethyl-2-pyrrolidone, 2-methyl-1,3-propanediol, tetraethyleneglycol, 1,6-hexanediol, 1,5-hexanediol and 1,5-pentanediol.

Further, one or more non-ionic, cationic, and/or anionic surfactant canbe present, ranging from 0.01 wt % to 20 wt %. In one example, thesurfactant can be present in an amount from 5 wt % to 20 wt %. Theliquid vehicle can also include dispersants in an amount from 5 wt % to20 wt %. Examples of surfactants that can be used include alkylpolyethylene oxides, alkyl phenyl polyethylene oxides, polyethyleneoxide block copolymers, acetylenic polyethylene oxides, polyethyleneoxide (di)esters, polyethylene oxide amines, protonated polyethyleneoxide amines, protonated polyethylene oxide amides, dimethiconecopolyols, substituted amine oxides, and the like. The amount ofsurfactant added to the formulation of this disclosure may range from0.01 wt % to 20 wt %. Suitable surfactants can include, but are notlimited to, liponic esters such as Tergitol™ 15-S-12, Tergitol™ 15-S-7available from Dow Chemical Company, LEG-1 and LEG-7; Triton™ X-100;Triton™ X-405 available from Dow Chemical Company; LEG-1, and sodiumdodecylsulfate.

Consistent with the formulation of this disclosure, various otheradditives can be employed to optimize the properties of the inkcomposition for specific applications. Examples of these additives arethose added to inhibit the growth of harmful microorganisms. Theseadditives may be biocides, fungicides, and other microbial agents, whichare routinely used in ink formulations. Examples of suitable microbialagents include, but are not limited to, NUOSEPT® (Nudex, Inc.),UCARCIDE™ (Union carbide Corp.), VANCIDE® (R.T. Vanderbilt Co.), PROXEL®(ICI America), and combinations thereof.

Sequestering agents, such as EDTA (ethylene diamine tetra acetic acid),may be included to eliminate the deleterious effects of heavy metalimpurities, and buffer solutions may be used to control the pH of theink. From 0.01 wt % to 2 wt %, for example, can be used. Viscositymodifiers and buffers may also be present, as well as other additives tomodify properties of the ink as desired. Such additives can be presentat from 0.01 wt % to 20 wt %.

The balance of the formulation can be purified water, or other vehiclecomponents such as viscosity modifiers, materials for pH adjustment,preservatives, or the like. In one example, the liquid vehicle can bepredominantly water, e.g., more than 50 wt % water.

Table 1 shows the composition of an example of a photo curable ink,e.g., UV LED curable ink, formulation in accordance with the presentdisclosure. The ink can be formulated by mixing these ingredients or byother formulations. The pH of the ink can then be adjusted. In oneexample, the ingredients can be stirred for 30 minutes and then aqueouspotassium hydroxide can be added to adjust the pH to 7 to 12, or inother examples, from 8 to 10, or about 8.5. It is noted that thoughwater concentrations are listed as “balance,” it is understood that thebalance of components could included other liquid vehicle components orminor amounts of solids often present in inkjet ink compositions.

TABLE 1 Component Weight Percent Photo reactive binder   1-20% (UVreactive polymer) Photo active co-solvent 0.15-5% (sensitizer or photoinitiator) Photo initiator 0.05-10 Co-photo initiator  *0-10% Synergist  *0-5% Surfactant   0-20% Anti-kogation agent   0-5% Pigment 0.5-10%Organic Co-solvent (in addition 0.1-50% to the photo active co-solvent)Water (and any other additives) balance *As noted, when the photo activeco-photo initiator is included as a sensitizer, the co-photo initiatoris at greater than 0%. When the photo active co-photo initiator isincluded as a photo initiator, the synergist is at greater than 0%. Allthree components can likewise be present, e.g., the photo initiator, theco-photo initiator, and the synergist.

The photo curable ink can be used to print on a broad selection ofsubstrates including untreated plastics, flexible as well as rigid,porous substrates such as paper, cardboard, foam board, textile, andothers. The ink has a good adhesion on a variety of substrates. Thephoto curable ink also has a good viscosity, enabling good printingperformances and the ability to formulate inks suitable for inkjetapplication. In some examples, the ink can be formulated for thermalinkjet printing. The photo curable ink composition of the presentdisclosure provides for high printing speed and is very well suited fora use in digital inkjet printing.

The photo active co-solvents of the present disclosure can be stable inaqueous environments at pH from 7 to 12 or higher. Thus, the photocurable ink can be formulated to have a pH from 7 to 12 or higher. Insome examples, the photo curable ink can have a pH of 8 or higher, e.g.,8 to 12 or 8 to 10. In one specific example, the photo curable ink canhave a pH of about 8.5.

The photo reactive binder can include polymers or monomers thatpolymerize or cross-link during the UV curing process. As the bindercures, the photo active co-solvent can become cross-linked therewith.

As mentioned, the present disclosure also extends to a method of makinga photo curable ink, as shown generally at FIG. 2. The method includesmixing 210 a photo reactive binder; a photo initiator, a co-photoinitiator, a synergist, or combination thereof; a colorant; and a liquidvehicle. The liquid vehicle can include water and anacrylamide-containing photo active co-solvent including a bis-trispropane co-solvent or a polypropylene oxide amine co-solvent reactedwith an acryloyl group. The photo curable ink can be UV curable, and inone specific example, UV LED curable. In one example, the method canalso include adjusting the pH of the ink to be from 7 to 12. In anotherexample, the method can include adjusting the pH of the ink to from 8 to10.

It is to be understood that this disclosure is not limited to theparticular process steps and materials disclosed herein because suchprocess steps and materials may vary somewhat. It is also to beunderstood that the terminology used herein is used for the purpose ofdescribing particular examples only. The terms are not intended to belimiting because the scope of the present disclosure is intended to belimited only by the appended claims and equivalents thereof.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise.

As used herein, “photo initiator” refers to materials that participatein the initiation of photo polymerization. The photo initiatorsdisclosed herein can be used either as a photo initiator or as asensitizer for another photo initiator. In some systems, the photoactive co-solvent can act as both a photo initiator and a sensitizer.

As used herein, “UV curable” refers to compositions that can be cured byexposure to ultraviolet light from any UV source such as a mercury vaporlamp, UV LED source, or the like. Mercury vapor lamps emit highintensity light at wavelengths from 240 nm to 270 nm and 350 nm to 380nm. There are also ultraviolet LEDs are available at 365 nm and 395 nmwavelengths, among others. “LED curable” refers to compositions that canbe cured either by ultraviolet light from an ultraviolet source, such asan Ultraviolet LED (or UV LED) which emits light at a specificwavelength. The term “photo curable” refers generally to compositionsthat can be cured by exposure to light from any wavelength suitable forthe composition being cured. Typically, the photo curable compositionwill be UV curable, and in some cases UV LED curable.

As used herein, “liquid vehicle” or “ink vehicle” refers to a liquidfluid in which colorant is placed to form an ink. A wide variety of inkvehicles may be used with the systems and methods of the presentdisclosure. Such ink vehicles may include a mixture of a variety ofdifferent agents, including, surfactants, solvents, co-solvents,anti-kogation agents, buffers, biocides, sequestering agents, viscositymodifiers, surface-active agents, water, etc.

As used herein, “colorant” can include dyes and/or pigments.

As used herein, “dye” refers to compounds or molecules that absorbelectromagnetic radiation or certain wavelengths thereof. Dyes canimpart a visible color to an ink if the dyes absorb wavelengths in thevisible spectrum.

As used herein, “pigment” generally includes pigment colorants, magneticparticles, aluminas, silicas, and/or other ceramics, organo-metallics orother opaque particles, whether or not such particulates impart color.Thus, though the present description primarily exemplifies the use ofpigment colorants, the term “pigment” can be used more generally todescribe not only pigment colorants, but other pigments such asorganometallics, ferrites, ceramics, etc. In one specific example,however, the pigment is a pigment colorant.

As used herein, “ink-jetting” or “jetting” refers to compositions thatare ejected from jetting architecture, such as ink-jet architecture.Ink-jet architecture can include thermal or piezo architecture.Additionally, such architecture can be configured to print varying dropsizes such as less than 10 picoliters, less than 20 picoliters, lessthan 30 picoliters, less than 40 picoliters, less than 50 picoliters,etc.

As used herein, the term “substantial” or “substantially” when used inreference to a quantity or amount of a material, or a specificcharacteristic thereof, refers to an amount that is sufficient toprovide an effect that the material or characteristic was intended toprovide. The exact degree of deviation allowable may in some casesdepend on the specific context.

As used herein, the term “about” is used to provide flexibility to anumerical range endpoint by providing that a given value may be “alittle above” or “a little below” the endpoint. The degree offlexibility of this term can be dictated by the particular variable anddetermined based on the associated description herein.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary.

Concentrations, amounts, and other numerical data may be expressed orpresented herein in a range format. It is to be understood that such arange format is used merely for convenience and brevity and thus shouldbe interpreted flexibly to include not only the numerical valuesexplicitly recited as the limits of the range, but also to includeindividual numerical values or sub-ranges encompassed within that rangeas if each numerical value and sub-range is explicitly recited. As anillustration, a numerical range of “about 1 wt % to about 5 wt %” shouldbe interpreted to include not only the explicitly recited values ofabout 1 wt % to about 5 wt %, but also include individual values andsub-ranges within the indicated range. Thus, included in this numericalrange are individual values such as 2, 3.5, and 4 and sub-ranges such asfrom 1-3, from 2-4, and from 3-5, etc. This same principle applies toranges reciting only one numerical value. Furthermore, such aninterpretation should apply regardless of the breadth of the range orthe characteristics being described.

EXAMPLES

The following illustrates several examples of the present disclosure.However, it is to be understood that the following are only illustrativeof the application of the principles of the present disclosure. Numerousmodifications and alternative compositions, methods, and systems may bedevised without departing from the spirit and scope of the presentdisclosure. The appended claims are intended to cover such modificationsand arrangements.

Example 1 Synthesis of Photoactive Co-Solvent 1

To a solution of bis-tris propane (56.5 g, 0.2 mol) in 200 ml of dry THFin a three-necked round bottom flask with mechanical stir was addedtrimethylamine (40.52 g, 0.4 mol) at room temperature. The resultingsolution was cooled down to 0° C. under N₂, then a solution of acryloylchloride (36.2 g, 0.4 mol) in 100 ml of dry THF was added dropwise at 0°C. After the addition was complete, the mixture was allowed to warm toroom temperature and continued to stir at room temperature forovernight. The white solid was collected by filtration and washed withTHF (3×50 ml). The combined THF filtrate and THF washing solutions wereevaporated off to give a residue. The residue was dissolved into 500 mlof chloroform and washed with saturated sodium bicarbonate aqueoussolution (3×100 ml) until no gas generated. The chloroform layer wasthen dried with sodium sulfate. Sodium sulfate was removed by filtrationand the filtrate was evaporated off to give the desired BIS TRIS Propanediacrylamide (BTPDA, Photo Active Co-solvent-1) (50.7 g, 65%).

Example 2 Synthesis of Photoactive Co-Solvent IV

To a solution of Jeffamine® ED 900 (100 g, 0.11 mol) in 250 ml of dryTHF in a three-necked round bottom flask with mechanical stir was addedtrimethylamine (22.66 g, 0.22 mol) at room temperature. The resultingsolution was cooled down to 0° C. under N₂, and then a solution ofacryloyl chloride (19.91 g, 0.22 mol) in 50 ml of dry THF was addeddropwise at 0° C. After the addition was complete, the mixture wasallowed to warm to room temperature and continued to stir at roomtemperature overnight. The white solid was collected by filtration andwashed with THF (×50 ml). The combined THF filtrate and THF washingsolutions were evaporated off to give a residue. The residue wasdissolved into 500 ml of chloroform and washed with saturated sodiumbicarbonate aqueous solution (×100 ml) until no gas generated. Thechloroform layer was then dried with sodium sulfate. Sodium sulfate wasremoved by filtration and the filtrate was evaporated off to give thedesired Jeffamine® 900 diacryloylamide (JA-900 DA) (100 g, 90 wt %).

Example 3 Synthesis of Photoactive Co-Solvent V

To a solution of Jeffamine® T-403 (100 g, 0.2273 mol) in 250 ml of dryTHF in a three-necked round bottom flask with mechanical stir was addedtrimethylamine (70.246 g, 0.682 mol) at room temperature. The resultingsolution was cooled down to 0° C. under N₂, then a solution of acryloylchloride (61.7 g, 0.682 mol) in 100 ml of dry THF was added dropwise at0° C. After the addition was complete, the mixture was allowed to warmto room temperature and continued to stir at room temperature forovernight. The white solid was collected by filtration and washed withTHF (×50 ml). The combined THF filtrate and THF washing solutions wereevaporated off to give a residue. The residue was dissolved into 500 mlof chloroform and washed with saturated sodium bicarbonate aqueoussolution (×100 ml) until no gas generated. The chloroform layer was thendried with sodium sulfate. Sodium sulfate was removed by filtration andthe filtrate was evaporated off to give the desired Jeffamine® T-403triacryloylamide (JA-T-403 TA) (116 g, 85%).

Example 4 Ink Testing Results

Curable water based inks were formulated based on the followingformulations found in Table 2:

TABLE 2 Component of Photo Curable Ink Wt % Surfynol ® CT-211 0.8(surfactant from Air Products) DX-4000 0.5 (fluorosurfactant from Dynax)TPO Na (photo initiator 0.5 CAS No. 2029-29-1) Irgacure ® 2959 0.25(co-photo initiator from BASF) Irgacure 819 0.2 (co-photo initiator fromBASF) Thioxanthone derivative of 0.25 PEG-350 (sensitizer) Photo CurablePolyurethane 10 Dispersion (cPUD—with or without added photoactiveco-solvent) Magenta Pigment 4 (from DIC Corp.) Water Balance

The inks of Table 2 (without photo active co-solvent and with addedphoto-active solvent) were printed or drawn-down on plastic media andthe following tests were performed to evaluate durability: a) Eraser rubat 1 weight (250 g) for 10 cycles; b) Windex rub at 1 weight (250 g) for5 cycles using a crockmeter cloth; c) Water rub at no weight (0 g) for 1cycle using a crockmeter cloth; d) 70 wt % isopropyl alcohol (IPA) rubat 1 weight (250 g) for 5 cycles using a crockmeter cloth; and e) Paperclip scratch test. Durability of ink films was evaluated by thefollowing test criteria (visual evaluation): 1-5, where 5 indicates fail(ink is fully removed), and 1 means excellent rub resistance. Thedurability for each ink is found in Table 3, as follows:

TABLE 3 Eraser Windex 70% IPA Water Paper Photo Curable Rub Rub Rub RubClip Ink UV-LED UV-LED UV-LED UV-LED UV-LED cPUD 4 4 4 4 5 cPUD with 1.51 2 1 2 7 wt % Photo Active Co-solvent IV cPUD with 3 2.5 3 1 3 5 wt %Photo Active Co-solvent IV

As can be seen in Table 3, there is a trend of improvement of durabilityacross the board with the addition of Photo Active Co-solvent IV. Theink film with only the photo curable polyurethane dispersion came closeto or failed all of the tests; while adding even 5 wt % of JA900DAimproved the durability across the board, especially for the water rub.With 7 wt % of Photo Active Co-solvent IV, all of the durability tests,including the 70 wt % IPA and paper clip scratch test, passed.

Table 4 below provides some of the properties for the inks prepared inaccordance with Table 2 above, as well as a comparative ink with addedmonomer from Sartomer instead of the cPUD component, as follows:

TABLE 4 Ink with Ink with Ink cPUD + 7 cPUD + 5 Time and with wt % Photowt % Photo Ink with Con- cPUD Active Co- Active Co- Sartomer ditionsonly solvent IV solvent IV monomer Vis- T-0 at 2.503 3.37 3.128 4.444cosity 25° C. (cPs) T-1 week 2.507 3.628 3.223 4.015 at 50° C. % Δ 0.16%7.65% 3.04%  −9.65% Particle T-0 at 123.3 120 126 4010 Size 25° C. (nm)T-1 week 130.5 131 131 3304 at 50° C. % Δ 5.80% 9.16% 3.97% −17.61% pHT-0 at 9.16 8.45 8.42 8.04 25° C. T-1 week 9.05 7.93 7.93 7.14 at 50° C.% Δ 0.11 0.52 0.49 0.9

Table 4 demonstrated compatibility of Photo Active Co-solvent IV withother ingredients of the UV-LED curable inks. The ink containing onlythe cPUD had excellent stability including viscosity, particle size, andpH stability. While adding 5 wt % or 7 wt % of Photo Active Co-solvent,the stability of the inks slightly decreased but still within acceptablerange. At the same time, the ink containing the commercial monomer fromSartomer had poor stability, especially with respect to particle sizeand pH drop.

Table 5 below provides further detail with respect to Eraser Rub, WindexRub, Water Rub, and Paper Clip scratch testing as it relates to additionof 7 wt % Photo Active Co-solvent IV to ink. In this example, a score of5 is considered to be failing, whereas 2 or lower is considered to beacceptable. In this example, a slightly different cPUD was used. Inthese examples, a draw down application method was used, and no fixerwas applied. The inks, as before, were the magenta inks of Table 2, andthe inks were applied to SAV

TABLE 5 Eraser Windex Water Paper Photo Curable Ink Cured? Rub Rub RubClip cPUD No 5 4 4 5 Yes 2 0.5 0.5 5 cPUD with cPUD + 7 wt % No 5 4 4 5Photo Active Co-solvent IV Yes 1 1 1 2

As can be seen, after curing in the presence of the Photo ActiveCo-solvent, the Eraser Rub, the Windex Rub, and the Water Rub remainedvery good, but the Paper Clip Scratch test was far superior compared tothe cPUD only inks.

While the present technology has been described with reference tocertain examples, those skilled in the art will appreciate that variousmodifications, changes, omissions, and substitutions can be made withoutdeparting from the spirit of the disclosure. It is intended, therefore,that the disclosure be limited only by the scope of the followingclaims.

What is claimed is:
 1. An acrylamide-containing photo active co-solvent,comprising a bis-tris propane co-solvent modified with an acryloyl groupto form the acrylamide-containing photo active co-solvent, wherein theacrylamide-containing photo active co-solvent has the followingstructure:


2. A photo curable ink, comprising: a photo reactive binder; a photoinitiator; a co-photo initiator, a synergist, or combination thereof; acolorant; and a liquid vehicle including water and a bis-tris propaneco-solvent modified with an acryloyl group to form anacrylamide-containing photo active co-solvent, wherein theacrylamide-containing photo active co-solvent has the followingstructure:


3. A method of preparing a photo curable ink, comprising mixing a photoreactive binder; a photo initiator; a co-photo initiator, a synergist,or combination thereof; a colorant; and a liquid vehicle, wherein theliquid vehicle includes water an acrylamide-containing photo activeco-solvent comprising a bis-tris propane co-solvent modified with anacryloyl group to form an acrylamide-containing photo active co-solvent,wherein the acrylamide-containing photo active co-solvent has thefollowing structure:


4. The photo curable ink of claim 2, wherein the photo reactive binderincludes a UV or LED curable polyurethane, a hydrophobicradiation-curable monomer, or a water dispersible (meth)acrylatedpolyurethane.
 5. The photo curable ink of claim 2, wherein the photoinitiator is a Type I photo initiator.
 6. The photo curable ink of claim2, wherein the photo initiator is a Type II photo initiator.
 7. Thephoto curable ink of claim 2, wherein the co-photo initiator is presentin the photo curable ink.
 8. The photo curable ink of claim 2, whereinthe synergist is present in the photo curable ink.
 9. The photo curableink of claim 8, wherein the synergist is an amine synergist selectedfrom trimethylamine, triethanolamine, methyldiethanolamine,phenyldiethanolamine, N,N,N′,N′-tetra(hydroxylethyl)ethylenediamine,dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethyldimethylaminobenzoate, or a combination thereof.
 10. The photo curableink of claim 2, wherein the photo initiator includes a radical photoinitiator selected 1-hydroxy-cyclohexylphenylketone, benzophenone,2,4,6-trimethylbenzo-phenone, 4-methylbenzophenone,diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, phenyl bis(2,4,6trimethylbenzoyl)phosphine oxide,2-hydroxy-2-methyl-1-phenyl-1-propanone, benzyl-dimethyl ketal,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, alpha aminoketone, bis acylphosphine oxide (BAPO), alpha hydroxy ketone, or acombination thereof.
 11. The photo curable ink of claim 2, wherein thecolorant includes a pigment.
 12. The method of claim 3, wherein thephoto reactive binder includes a UV or LED curable polyurethane, ahydrophobic radiation-curable monomer, or a water dispersible(meth)acrylated polyurethane.
 13. The method of claim 3, wherein thephoto initiator is a Type I photo initiator.
 14. The method of claim 3,wherein the photo initiator is a Type II photo initiator.
 15. The methodof claim 3, wherein the co-photo initiator is present in the photocurable ink.
 16. The method of claim 3, wherein the synergist is presentin the photo curable ink.
 17. The method of claim 3, wherein thesynergist is an amine synergist selected from trimethylamine,triethanolamine, methyldiethanolamine, phenyldiethanolamine,N,N,N′,N′-tetra(hydroxylethyl)ethylenediamine, dimethylaminoethylacrylate, dimethylaminoethyl methacrylate, ethyl dimethylaminobenzoate,or a combination thereof.
 18. The method of claim 3, wherein the photoinitiator includes a radical photo initiator selected1-hydroxy-cyclohexylphenylketone, benzophenone,2,4,6-trimethylbenzo-phenone, 4-methylbenzophenone,diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, phenyl bis(2,4,6trimethylbenzoyl)phosphine oxide,2-hydroxy-2-methyl-1-phenyl-1-propanone, benzyl-dimethyl ketal,2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, alpha aminoketone, bis acylphosphine oxide (BAPO), alpha hydroxy ketone, or acombination thereof.
 19. The method of claim 3, wherein the colorantincludes a pigment.